BHA

Butylated hydroxyanisole (BHA) is a synthetic antioxidant that is mainly added to fish oil to prevent the fat from going rancid.

Fish oil is used as an ingredient in fish feed, and some BHA is therefore present in that fish feed. BHA is less widely used than the other synthetic antioxidants. It is used in some food products such as cake mixes, snacks and powdered milk. In seafood it is found at very low levels in farmed salmon that has been given feed containing BHA.

There is no evidence of exposure to BHA causing any harm to humans, but experiments on rats have shown that it can be carcinogenic if taken in large doses.